Liquid crystal display (LCD) has advantages such as light weight, low power consumption, ease driving operation and non-harmful-radiation, has been widely used in a television, a notebook computer, a mobile phone, a person digital assistant and other modern information equipment and obtains a wide development. As a LCD itself emit no light, a backlight source is usually provided at a back face of the LCD to achieve an image display.
In order to increase a contrast of an image displayed on a LCD and improve a dynamic smear of the LCD, a high dynamic contrast range (HDR) technology appears recently, which can increase brightness range while increasing a contrast between an image with highest brightness and a darkest image. The high dynamic contrast range technology may not only bring a wider color gamut but also achieve color effect of whiter or blacker such that a user may view more detail of an image, thereby largely improving display effect. The high dynamic contrast range technology is applied to divide a backlight source into a plurality of areas in a certain direction, each area being called as a partitioning block, which may be rectangular, and meanwhile, to divide a LCD into a plurality of partitioning blocks corresponding to those of the backlight source. A projection of each of the partitioning blocks of the backlight source is of superposition with a projection of each partitioning block of the LCD, which is located over the backlight source, in a vertical direction. Light from each partitioning block of the backlight source is incident to the LCD for displaying an image and the light and dark contrast of the image displayed is achieved by individually adjusting the brightness of each partitioning block of the backlight source.
Generally, the higher the high dynamic contrast range is, the better the display effect is. In addition, a contrast value for the HDR prescribed by the HDR industry standard is 10000:1, even 20000:1. When a HDR contrast value is 20000:1, a brightness of an image displayed is 1000 nits in a bright state and is 0.05 nits in a dark state. In order to obtain a higher HDR contrast value, the number of the partitioning blocks of the backlight source is set as more as possible.
It is needed to provide an ultrathin display device with a higher dynamic contrast.